Ink and dampener form roll interruption for cleaning purposes

ABSTRACT

A lithographic printing press includes a rotatable plate cylinder for carrying a printing plate. An ink distribution system applies ink to the plate, and a dampener solution distribution system applies a dampening solution to the plate. Both the ink distribution system and the dampening solution distribution system include form rolls which have a cooperative fluid-transferring relationship with the plate. The dampener form roll carries both ink and dampening solution during printing. During wash-up or cleaning of the ink distribution system, the form rolls of the ink distribution system are moved away from the plate cylinder, and an ink-cleaning solution is distributed through the system. In accordance with the present invention, means is provided for transmission of the ink-cleaning solution from the ink distribution system to at least the dampener form roll to effect cleaning of at least the dampener form roll during cleaning of the ink distribution system.

United States Patent Sylvester et a]. 1451 Oct. 31, 1972 s41 INK AND DAMPENER FORM ROLL 2,363,817 11/1944 Taylor ..101/350 INTERRUPTION FOR CLEANING 1.058.040 4/1913 Crump ..101/425 PURPOSES 3,168,037 2/1965 Dahlgren ..101/14a Inventors: Peter A. Sylvester, Dayton; Walter .1. Wnjciechowskl, Cleveland, both of Ohio Harris lntertype Corporation, Cleveland, Ohio Filed: May 18, 1970 Appl. No.: 38,009

Assignee:

References Cited UNITED STATES PATENTS Biittner ..l01/425 X Domotor ..101/l48 X Wojciechowski et al ..lOl/l48 Fudala.......................101/425 Davidson...................101/352 Norton ......................101I148 Primary Examiner-.1. Reed Fisher Attorney-Yount & Tarolli ABSTRACT A lithographic printing press includes a rotatable plate cylinder for carrying a printing plate. An ink distribution system applies ink to the plate, and a dampener solution distribution system applies a dampening solution to the plate. Both the ink distribution system and the dampening solution distribution system include form rolls which have a cooperative fluid-transferring relationship with the plate. The dampener form roll carries both ink and dampening solution during printing. During wash-up or cleaning of the ink distribution system, the form rolls of the ink distribution system are moved away from the plate cylinder, and an inkcleaning solution is distributed through the system. in accordance with the present invention, means is provided for transmission of the ink-cleaning solution from the ink distribution system to at least the dampener form roll to effect cleaning of at least the dampener form roll during cleaning of the ink distribution system.

3 Claims, 5 Drawing Figures minimum n 3701.316

SHEET 1 (IF 3 INVEN TOES PETE)? ,4. SYN/572? 2 I164! IZP d IVOJC/ECl/OIVS'K/ PATENTEmcm I972 I/VVENTORS PETER /7- 57 V55 W141??? d. WOJC/E'CHOWSK/ ATTORNEYS [NR AND DAMPENER FORM ROLL INTERRUPTION FOR CLEANING PURPOSES The present invention relates to improvements in a lithographic printing press having an ink distribution system and a dampener distribution system, and particularly relates to the cleaning of the dampener distribution system with the ink distribution system.

As is well known in the printing art, the ink distribution system of a printing press is periodically cleaned. The cleaning is effected by the use of a cleaning solution which is transferred throughout the ink distribution system, the cleaning solution being in the form of an appropriate ink solvent. Heretofore, the solvent has been sprayed on various ones of the rollers of the ink distribution system and then transmitted throughout the ink distribution system by rotation of the roller thereof while in contact with each other. At this time, there is no ink feed, and the usual form rollers of the inker are out of contact with the plate on the plate cylinder. The solvent and dissolved ink have been collected in a trough for purposes of disposal. A patent showing this general arrangement is U.S. Pat. No. 2,970,541, and reference may be made thereto for details of such a system.

While ink distribution systems have been cleaned in the manner noted hereinabove, the cleaning and removal of the ink from dampening solution distribution systems has not been so simplified for all dampener constructions. In the case of a dampener construction in which the dampener form roll is a part of the inker and receives a film of ink as well as a film of dampening solution, the dampener form roll is cleaned by the ink cleaning solution, since it is in effect a part of the inker rather than independent therefrom. However, in the case of a dampener construction in which the dampener form roll is not a part of the inker, the dampener form roll is not cleaned by the ink cleaning solution, as described above, since the dampener form roll is independent of the inker rather than a part thereof.

The U.S. Pat. No. 2,810,344 offers a suggestion for cleaning the dampener where the dampener form roll is independent of the inker. The ink which is received by the dampener form roll most commonly has been removed therefrom by manual cleaning thereof. This patent, however, involves the use of a roll which must be inserted into the press for purposes of cleaning and than removed therefrom after cleaning. The roll transmits cleaning solution from the inker to the dampener to thereby effect cleaning thereof. The patent, however, incorporates in the dampener, rolls which have a felt-type covering which are substantially absorbent and which require substantial scrubbing in order to effect cleaning thereof. Once the felt rolls are cleaned, a substantial period of time is required until the felt rolls dry and. therefore, the press is down for a substantial amount of time.

The present invention is directed to the problem of cleaning the ink from a dampener and, particularly, the dampener form roll and which is completely separate or independent of the ink distribution system. Moreover, the present invention is directed to solving the problem of the cleaning of the dampener form roll by contact of the ink-cleaning solution with the surface thereof. This is accomplished without ink-cleaning solvent being transmitted through the entire dampener solution distribution system.

Accordingly, the system embodying the present invention does not require any roll of the dampener solution distribution system to be a part of or in contact with the ink distribution system during printing, nor does the system require absorbent rolls which require scrubbing and considerable time for drying. And yet, the present system provides a simple mechanism which can be utilized for effecting cleaning of both the ink distribution system and ink-attractive portions of the dampener distribution system simultaneously by incorporating therein means for providing for the transmission of the ink-cleaning solution from the ink distribution system to the dampening form roll during cleaning of the system.

According y, the principal abject of the present invention is the provision of a new and improved lithographic printing press in, which the ink distribution system and portions of the dampener distribution system can be cleaned simultaneously by ink-cleaning solution which is transmitted from the ink distribution system to the dampener distribution system and wherein the construction does not require that any part of the dampener distribution system form a part of the ink distribution system during printing, nor does the construction incorporate absorbent rolls or require the insertion and removal of a separate roll from the system for cleaning purposes.

Another object of the present invention is to provide for clean-up of only the ink-attractive portions of the dampener system with the inker, thereby avoiding the adverse affect that ink solvent would have on the inkrejecting portions of the dampener while also eliminating the need to remove solution from the dampener system during ink clean-up.

A further object of the present invention is the provision of a new and improved lithographic printing press having a dampener form roll which may be cleaned by contact of the ink-cleaning solution with the surface thereof and wherein means is provided for effecting the transmission of ink-cleaning solution from the ink distribution system to the dampener form roll to effect cleaning of at least the dampener form roll during cleaning of the ink distribution system by the ink-cleaning solution.

Another object of the present invention is the provision of a new and improved lithographic printing press having a dampener form roll with a surface which can be cleaned by contact of an ink-cleaning solution with the surface thereof, and wherein means is provided for shifting the dampener form roll for cleaning purposes into a position to receive ink-cleaning solution from the ink distribution system to effect cleaning of at least the dampener form roll during cleaning of the ink distribution system.

A still further object of the present invention is the provision of a new and improved lithographic printing press, as noted in the next preceding paragraph, wherein the means providing for the transmission of the ink-cleaning solution comprises a roll which runs in contact with either an ink form roll or the dampener form roll and which is shifted into engagement with the other of the form rolls in order to provide for the transmission of ink-cleaning solution therebetween during cleaning.

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from a consideration of the following detailed description thereof made with reference to the accompanying drawings in which:

FIG. 1 is a schematic representation of a portion of a lithographic printing press showing the inker and dampener therefor;

FIG. 2 is an enlarged fragmentary schematic view of a portion of the press of FIG. 1;

FIG. 3 is a view similar to FIG. 2 but showing parts thereof in a different position;

FIG. 4 is a fragmentary schematic view of a modified embodiment of the present invention; and

FIG. 5 is still another schematic view illustrating a still further modified embodiment of the present invention.

The present invention provides an improved lithographic printing press, and particularly an improved press which provides for simultaneous cleaning of both the ink distribution system and a portion of the dampening solution distribution system. This invention provides for the simultaneous cleaning of both the ink distribution system and the dampener solution distribution system without the necessity of a roll of the dampener forming a part of the inker during printing or the necessity for the insertion and removal of a separate cleaning roll in the system.

By way of schematic representation, the present invention is illustrated as applied to a printing press 10. The printing press is a lithographic printing press having a plate cylinder 11 which runs in contact with a blanket cylinder and which blanket cylinder, in turn, cooperates with an impression cylinder to print on material which is transmitted therebetween. The blanket and impression cylinders are of conventional construction and are not illustrated herein. An ink distribution system, generally designated 12, is provided in the press 10 for applying ink to a printing plate supported on the plate cylinder 11. Additionally, a dampener or dampening solution distribution system, generally indicated I4, is provided for applying dampening solution to the plate carried by the plate cylinder 11.

The ink distribution system 12 cooperates to transmit ink from a fountain or supply 15 to the plate on the plate cylinder 11. The ink distribution system includes a plurality of rolls which include a ductor roll 17 which moves between a fountain roll 18 and an ink-transmitting roll 19. Rubber or composition ink-transmitting rolls cooperate to transmit ink through the distribution system and to the ink form rolls 19a, 20, 2] and 22, which have during printing a co-operative ink-transferring relationship with the plate on the plate cylinder 11. The ink distribution system also includes a plurality of metal vibrator rolls 23, 24 and 25 which, as is well known, move axially as well as rotationally.

The inker arrangement illustrated in FIG. 1 is merely for illustrative purposes and not in any limiting of the present invention. The rollers of the inker are shown in exaggerated conditions in some instances for purposes of simplicity. It should be apparent that changes could be made therein. It should also be apparent that no specific drive for rotating the rolls of the inker has been illustrated, since the drive for the inker does not form a part of the present invention and any drive arrangement may be utilized.

As is well known, for many purposes relating to the operation and setup of the printing press, the ink form rolls 19a, 20, 21 and 22 are movable or shiftable away from the plate cylinder 11. There are a plurality of mechanisms which may be utilized for such shifting of the form rolls. As illustrated in the drawing schematically, a suitable mechanism 27 is provided for shifting the form rolls 2], 22 relative to the vibrator 25 and away from the plate cylinder 11. The mechanism 27 includes a cam 27a having flats which engage the respec tive arms which carry the form rolls 21, 22. Rotation of the cam 270 causes the respective arms to move in opposite directions to a thrown-off position, as illustrated in FIG. 3. The arms are spring biased against the cam 27a and upon rotation of the cam 27a to its position illustrated in FIG. 2, move the form rolls 2], 22 toward the cylinder 11. The respective arms pivot by action of the cam 27a about the axis of the metal vibrator roll 25. In this manner, the form rolls 2], 22 can be moved away from the plate cylinder 11 to their thrown-off position, but are still in a cooperative solution-transmitting relation with the vibrator 25. The specific construction of the mechanism 27 for moving the form roll or shifting the form roll out of engagement with the plate cylinder will be described in greater detail in view of the fact that any conventional construction may be utilized and anyone skilled in the art can provide such.

The dampener or dampener solution distribution system 14 of the present invention may take many forms. With regard to the embodiment of FIGS. 1-3, the dampener distribution system includes a dampener form roll 30 which runs in cooperative relationship with the plate cylinder 11 and applies a dampening solution to the plate thereon. The dampening form roll 20 is a so-called bareback" roll and has a relatively non-absorbent rubber or composition outer surface. The roll 30 carries both dampening solution and ink during the normal printing operation. The surface of the roll is receptive to both ink and dampening solution. The dampener form roll 20 cooperates with a chrome roll 31 which is ink-rejecting. The chrome roll 31 transfers dampening solution to the dampener form roll 20, but does not receive any ink from the roll 30 because of the fact that the chrome roll is ink-rejecting.

The dampener system 14 also includes a dampener solution-transmitting roll 32 which transmits dampening solution from a chrome supply roll 33 which cooperates with the supply of dampening solution 34, and the roll 32 transmits the dampening solution to the ink-rejecting roll 31. The rolls 32 and 33 may be driven at the same speed from a variable speed drive motor, as is described in U.S. Pat. No. 3,433,155. The form roll 30 and the ink-rejecting roll 31 may be driven at press speed in any suitable manner and slip may occur between the roll 31 and the roll 32, as is known to be desirable, and provide for metering of the flow of dampening solution from the supply to the dampener form roll 30. The roll 30 has associated with it a throwoff mechanism, generally designated 36. The throwoft' mechanism 36 is operable to throw the form roll 30 away from the plate cylinder 11.

It should be apparent from the above description that the printing press described hereinabove includes a dampener wherein the dampener form roll 30 does not form a part of the ink distribution system, but rather the dampener form roll 30 is completely separate and independent of the ink distribution system. The ink which is received in the dampener form roll 30 is received directly from the printing plate and not from the ink distribution system. In addition, it should be apparent that the dampener form roll 30 is a non-absorbent roll as opposed to a felt-covered or cloth-covered roll.

As noted hereinabove, the cleaning of an inker and dampener of a press has involved certain problems. The cleaning of the inker has been accomplished in the manner described in U.S. Pat No. 2,970,541. A suitable inker wash-up device has been provided in the press and which is generally indicated 40 in FIG. I. The inker wash-up device 40 includes a trough 41 and a blade 42 which engages one of the rolls in the ink distribution system. As illustrated in FIG. 1, the blade 42 engages the roll 23 of the ink distribution system. A suitable ink solvent is sprayed onto the rolls by a nozzle 43 and the solvent is then transmitted throughout the ink distribution system due to the fact that the rolls of the system are driven as the solvent is sprayed onto the roll 23 and the rolls are in a solution-transmitting relation. As the solvent iis transmitted through the ink distribution system, the solvent functions to clean the bulk of the ink from .all of the rollers in the ink distribution system and the .dissolved ink is collected in the trough 41 for disposal. Alfinal wiping of the ink rolls with solvent rags is generally required to completely clean the system. The present invention is directed to the provision of the simultaneous cleaning of the dampener form roll 30 with the cleaning of the ink distribution system.

In accordance therewith, the printing press of the present invention includes means for providing for transmission of ink-cleaning solution from the ink distribution system to the dampener form roll to effect cleaning of at least the dampener form roll 30 during cleaning of the ink distribution system. The means for providing for transmission of ink-cleaning solution from the ink distribution system in the embodiment illustrated in FIG. 2 comprises the throwoff mechanism 36 which effect throw off of the dampener form roll 30 from the printing position shown in FIG. 2 to a cleaning position shown in FIG. 3. The throwoff mechanism 36 throws the dampener form roll 30 to the cleaning position of FIG. 3 out of contact with the plate cylinder and away from the ink-rejecting chrome roll 31. The dampener form roll cooperatively engages the ink form roll 22 when these rolls are located in their thrown-off positions for purposes of cleaning, illustrated in full lines in FIG. 3.

When the ink form roll 22 and the dampener form roll 30 are in their cleaning positions, as illustrated in FIG. 3, the ink-cleaning solution which is applied to and transmitted through the ink distribution system 12 is also transmitted to the dampener from roll 30 and the dampener form roll 30 is cleaned thereby at the same time as the remainder of the ink distribution system. As a result. a separate manual operation for cleaning of the dampener form roll 30 is not necessary. The surface of the dampener form roll 30 is such that the dampener form roll 30 may be cleaned by contact of the cleaning solution with the surface thereof. Accordingly, it should be apparent that the throwoff mechanism 36 comprises a means for providing for the transmission of ink-cleaning solution from the ink distribution system to the dampener form roll 30 to effect simultaneous cleaning thereof.

The throwoff mechanism 36 for the dampener form roll 30 also can effect throwoff of the form roll 30 to an intermediate position, indicated in dotted lines in FIG. 2, and dot-dash lines in FIG. 3. In the intermediate position, the form roll 30 is out of engagement with the plate cylinder 11 and also out of engagement with the ink-rejecting roll 31. However, in the intermediate position, the form roll 30 is not in engagement with the ink form roll 25. This intermediate position would be the normal throwoff position of the form roll 30, for example, during makeready or when the press remains inoperative for long periods, such as overnight.

The throwoff mechanism 36 can be readily designed in order to provide a substantially greater distance of throw-off of the form roll 30 for purposes of cleaning and a smaller throw-off for other purposes. The throwoff mechanism 36 comprises a pair of eccentrics 37 located at the opposite ends of the dampener form roll 30 and each of which are associated with a bracket 38 which supports the opposite ends of the dampener form roll 30. Eccentrics 37 may be journalle'd on the fixed axis shaft 31a of roll 31. Rotation of the eccentrics 37 relative to the bracket 38 effects throw-off of the dampener form roll 30. Suitable guides 38a cooperate with the bracket 38 and guide the movement thereof by the eccentrics. For purposes of throwing the dampener form roll 30 to the intermediate position. the eccentric 37 may be rotated one distance. However, for throwing the dampener form roll 30 to the cleaning position, a greater rotation of the eccentric 37 is necessary, thereby resulting in a greater amount of movement of the dampener form roll 30. In order to effect rotation of the eccentric 37, the eccentric has an arm 39 associated therewith and a cam 39a is associated with the arm 39. Suitable means is provided under the control of the operator for effecting rotation of the cam 39:: a variable distance, depending upon whether or not the dampener form roll is to be moved only to its intermediate position or to its cleaning position. In the event that the dampener form roll 30 is to be moved to its intermediate position only, the cam is rotated at first distance. If the dampener form roll 30 is to be moved to its cleaning position, the cam 39a will be moved a second distance greater than the first distance. The design of the mechanism effecting a variable rotation of the cam 39a is not shown herein. since anyone skilled in the art can effect a proper design or suitable mechanism therefor.

The drive for driving the dampener form roll 30 has not been disclosed herein. For purposes of the present invention, the dampener form roll 30, as well as the chrome roll 31, preferably are driven due to the pressure engagement with their cooperating rolls. However, as is conventional, a gear drive may be provided between the plate cylinder 11 and the dampener form roll 30 to effect rotation of the dampener form roll therewith. Moreover, a suitable gear drive could be provided between the dampener form roll 30 and the roll 31 to efi'ect rotation thereof. In the event that a gear drive is provided therebetween, it should be realized that the throwoff arrangement would be designed such that the teeth of the gears completely come out of mesh with each other during throwoff movement of the dampener form roll. In such a case, the dampener form roll 30 would be driven frictionally by the ink form roll 22. Without the disengagement of the gear drive between the fonn roll 30 and the plate cylinder 1 I, the dampener form roll 30 and the ink form roll 22 would be driven in opposite directions by their respective drives when they are in cleaning position.

While the embodiment of FIGS. 1-3 has been described hereinabove in considerable detail, it should be apparent that the present invention could be applied different ways in a printing press construction. The embodiment of FIG. 4 is an embodiment which can equally as well be utilized to accomplish the advantages of the present invention. The embodiment of FIG. 4 includes a dampener distribution system which includes a bareback dampener form roll 51. The dampener form roll is completely independent of the ink distribution system. The ink distribution system includes an ink form roll 53 and a cooperating roll 54 which runs in contact with the ink form roll 53. When the ink form roll 53 is thrown off, the roll 54 is moved therewith. These rolls are shown in dotted lines in FIG. 4 in their thrown-off position. When the dampener form roll 51 is moved to its cleaning position, illustrated in dotted lines in FIG. 4, the dampener form roll 51 cooperatively engages the roll 54. As a result, during cleaning the ink-cleaning solution is transmitted from the ink form roll 53 to the additional roll 54 and then to the dampener form roll 51. In the thrown-off position for cleaning, which is illustrated in dotted lines in FIG. 4, the dampener form roll 51 is out of contact with the ink-rejecting roll 55 in the dampener distribution system. The dampener fonn roll 51 has an intermediate position but it is not shown for purposes of simplicity. Again, with regard to FIG. 4, the particular drive for the various mechanisms has not been shown, nor has the throwoff mechanism been illustrated, for purposes of simplifying the disclosure. However, the dampener form roll 51 can be gear driven from the plate cylinder. In this case, the gears of such a drive need not be completely disengaged when the dampener form roll 51 is moved to its cleaning position, since the surfaces of the additional roll 54 and dampener form roll 51 will be rotating in the same direction.

The embodiment of FIG. is similar to the embodiment of FIG. 4 in that an additional roll 60 is provided for transmitting the ink-cleaning solution from the ink form roll to the dampener form roll. However, the embodiment of FIG. 5 differs from that of FIG. 4 in that the roll 60 is normally a part of the dampening distribution system as opposed to roll 54 which is normally in the inker. The distribution system 61 includes a dampener form roll 62 which during printing has the fullline position of FIG. 5. The dampener form roll 62 in the embodiment of FIG. 5 is a non-absorbent roll and is completely independent of the inker and is of a construction similar to that described above in connection with FIG. 3. The roll 60, likewise, is completely independent of the inker during printing operation. For purposes of clean-up, a throwoff mechanism is provided for moving the form roll 62 from the full-line position shown in FIG. 5 to the dotted-line position. When the form roll 62 is moved to the dotted-line position, and out of engagement with the plate on the plate cylinder, the roll 60 is also moved. The roll 60 when thrown off engages the ink form roll 65 when it is in its thrown off position. The ink form roll is shown in a dotted position in FIG. 5 illustrating its thrown-off position for purposes of cleaning. This embodiment operates precisely in the manner described above in connection with the embodiment of FIG. 4 and the inkcleaning solution which is applied to the ink distribution system is also applied or transmitted to the dampener form roll 62 by means of roll 60. As in the FIG. 4 modification, the intermediate position of rolls 60 and 62 has not been illustrated.

It should be apparent from the above that three different modifications of the present invention have been described, all of which are directed to an improved lithographic printing press having a dampener form roll which is completely independent of the ink distribution system during printing, but which may be cleaned at the same time as the cleaning of the ink distribution system. This cleaning is effected by the provision of means for transmitting cleaning solution from the inker to the dampener form roll simultaneously with the cleaning of the ink distribution system.

Having described my invention, I claim:

1. In a lithographic printing press having a rotatable plate cylinder, means for applying ink to a plate on said plate cylinder comprising a first plurality of rolls forming an ink distribution system, means for applying a dampening solution to said plate comprising a second plurality of rolls forming a dampening solution distribution system, said first plurality of rolls including at least one ink form roll having a direct ink-transferring cooperative engagement with said plate during printing and shiftable therefrom to a thrown-off position, means for shifting said direct ink form roll from said ink-transferring cooperative engagement with said plate to said thrown-off position and from said thrown-off position into direct ink-transferring engagement with the plate, said second plurality of rolls including a dampener form roll and a dampener fluid-transmitting roll, said dampener form roll having a direct cooperative fluidtransmitting engagement with said plate and with said dampener fluid-transmitting roll during printing, said dampener form roll being spaced from said first plurality of rolls when said dampener form roll is in direct cooperative engagement with said plate and said dampener fluid-transmitting roll during printing, and means for shifting said dampener form roll from direct cooperative engagement with the plate and said dampener fluid-transmitting roll into direct cooperative fluid-transmitting engagement with said ink form roll when said ink form roll is in said thrown-off position.

2. In a lithographic printing press as defined in claim I wherein said means for shifting said dampener form roll includes means for moving said dampener form roll to an intermediate position between its printing position in cooperative engagement with the printing plate and its position in cooperative engagement with said ink form roll.

3. In a lithographic printing press as defined in claim 2 wherein said means for shifting said dampener form roll comprises support arm means rotatably supporting said dampener form roll and eccentric means supporting said support arm means and rotatable relative thereto.

I l I i 

1. In a lithographic printing press having a rotatable plate cylinder, means for applying ink to a plate on said plate cylinder comprising a first plurality of rolls forming an ink distribution system, means for applying a dampening solution to said plate comprising a second plurality of rolls forming a dampening solution distribution system, said first plurality of rolls including at least one ink form roll having a direct inktransferring cooperative engagement with said plate during printing and shiftable therefrom to a thrown-off position, means for shifting said direct ink form roll from said ink-transferring cooperative engagement with said plate to said thrown-off position and from said thrown-off position into direct inktransferring engagement with the plate, said second plurality of rolls including a dampener form roll and a dampener fluidtransmitting roll, said dampener form roll having a direct cooperative fluid-transmitting engagEment with said plate and with said dampener fluid-transmitting roll during printing, said dampener form roll being spaced from said first plurality of rolls when said dampener form roll is in direct cooperative engagement with said plate and said dampener fluid-transmitting roll during printing, and means for shifting said dampener form roll from direct cooperative engagement with the plate and said dampener fluid-transmitting roll into direct cooperative fluidtransmitting engagement with said ink form roll when said ink form roll is in said thrown-off position.
 2. In a lithographic printing press as defined in claim 1 wherein said means for shifting said dampener form roll includes means for moving said dampener form roll to an intermediate position between its printing position in cooperative engagement with the printing plate and its position in cooperative engagement with said ink form roll.
 3. In a lithographic printing press as defined in claim 2 wherein said means for shifting said dampener form roll comprises support arm means rotatably supporting said dampener form roll and eccentric means supporting said support arm means and rotatable relative thereto. 